Methods of manufacturing hollow bodies with separate elements enclosed therein

ABSTRACT

In a method of manufacturing in one piece a hollow body which is to accommodate in a hollow space thereof one or more separate elements which cannot possibly, or only with difficulty, be mounted in the body without division thereof, the separate elements are enclosed in a core and the body is then shaped in one piece on the core by casting or otherwise, whereupon the core is removed so that the separate means are uncovered in the hollow space in the body.

United States Patent Inventor Frans Harry Karlsson Lund, Sweden Appl.No. 812,160

Filed Apr. 1, 1969 Patented Sept. 14, 1971 Assignee Hykon-PatentAktiebolag Lund, Sweden Priority Apr. 10, 1968 Sweden 4825/68 METHODS OFMANUFACTURING HOLLOW BODIES WITH SEPARATE ELEMENTS ENCLOSED THEREIN 6Claims, 4 Drawing Flgs.

U.S. Cl 29/157,], 137/454.6, 251/148 Int. Cl. ..B2ld 53/00, B21k 29/00,823p 15/26 Field of Search 29/157. 1;

[56] References Cited UNITED STATES PATENTS 3,049,794 8/1962Bredtschneider 29/l57.1 3,081,792 3/1963 Hansen 29/157.l 3,100,5018/1963 Hansen... 137/4546 3,182,952 5/1965 Montesi.. 251/148 3,192,9487/1965 Anderson... 29/l57.l 3,271,845 9/1966 Breher.... 29/157.l

Primary Examiner-John F. Campbell Assistant Examiner-Donald P. RooneyAttorney-Beveridge & DeGrandi ABSTRACT: In a method of manufacturing inone piece a hollow body which is to accommodate in a hollow spacethereof one or more separate elements which cannot possibly, or onlywith difficulty, be mounted in the body without division thereof, theseparate elements are enclosed in a core and the body is then shaped inone piece on the core by casting or otherwise, whereupon the core isremoved so that the separate means are uncovered in the hollow space inthe body.

PATENTED SEPI4I97| 3504.089

SHEET 1 0F 4 INVENTOR. FRANS HARRY KARLsSQN by 61cm 514. 4% aww y,

I WW4 METHODS OF MANUFACTURING HOLLOW BODIES WI'II-ISEPARATE ELEMENTSENCLOSED THEREIN This invention relates to a method of manufacturing inone piece a hollow body which is to accommodate in a hollow spacethereof one or more separate elements which cannot possibly, or onlywith difficulty, be mounted in the body without division thereof.

l-Iollow bodies which are to contain separate elements must often bemade divisible to permit mounting the separate elements in the hollowspace of the body.

As examples of such bodies there may be mentioned valve housings whichare to contain valve members. For instance, the valve housings ofshutoff valves are usually cast in two parts, one part constituting thebody of the housing and the other part a cover which is connected to aflange of the body with the aid of bolts. The cover is usually cast witha box for a packing for the valve rod and besides has to be sealedrelative to the flange of the body of the valve housing by means of acover gasket. The disadvantage connected with this embodiment is thatthe seal between the cover and the remaining portion of the valvehousing will often become deficient after some time of use and has to bereplaced, which may prove very difficult and costly at certaininstallations. Also, it is basically more expensive to manufacture avalve housing in two parts with relatively good fitting between theparts than to manufacture the housing in one piece, if this werepossible. Moreover, the two-part embodiment described requires boring anumber of holes in the cover and the flange of the valve housing,mounting the valve member in the housing and assembling the valvehousing details. Some of these operations might be dispensed with if itwere possible to manufacture the valve housing in a single piece.-

This has now been made possible by the present invention, which relatesto the manufacture of a valve comprising a cast valve housing havinginlet and outlet ports and a movable valve member situated in saidhousing and operable via an operating means which extends through anopening in the valve housing. Characteristic of the method according tothe invention is that the valve member is manufactured and enclosed in acore and that the valve housing is cast in one piece on the core wherebythe valve member is enclosed in the housing, that the core is thenremoved through one of the ports of the valve housing for releasing thevalve member therein, and that the valve member is connected to theoperating means which is introduced for this purpose preferably fromoutside through an opening provided therefor in the valve housing.

Molding of the hollow body on the core can be performed by conventionalcasting methods and molding of the core can be performed according toconventional core molding methods, for instance the shell moldingmethod.

The method of the invention is particularly suited for easting valvehousings of metal in one piece around a metallic valve member enclosedin the core, said metallic valve member being preferably shaped and, asthe case may be, finished for immediate use to avoid inconvenient finalworking thereof in the interior of the valve housing.

The method of the invention is applicable to the manufacture of sluicevalves and other shutoff valves where special advantages are gained.

The invention will now be more fully described in the following by wayof example when applied to the manufacture of a low pressure typeshutoff valve, reference being made to the accompanying drawings inwhich:

FIG. I is an axial sectional view of a sluice valve;

FIG. 2 is a similar view showing the valve in FIG. 1 after casting ofthe valve housing but before removal of the core;

FIG. 3 is a cross-sectional view of the valve housing shown in FIG. 2taken at right angles to the axis of flow and showing the valve housingafter removal of the core but before mounting of the valve rod andpositioning of the sealing rings;

FIG. 4 is an axial sectional view of a shutoff valve having a conicalvalve member.

The valve shown in FIG. I is a sluice valve of the conventional typeexcept for the simplifications gained by the invention in casting thevalve housing in one piece. The valve housing comprises a lower bodyhaving an inlet and an outlet connecting socket 2, 3, and an upper body4 cast integrally with the lower body and accommodating the slide-typevalve member 5 in the open position thereof. At the mouth of each socket2, 3 leading into the bore of the valve housing there is formed a seatwhich is an annular groove with a sealing ring 6 and 7, respectively,therein. The valve member or slide 5 substantially is in the form of adisk having an annular sealing surface on each side for applicationagainst the sealing rings 6 and 7. These sealing surfaces on the slideare formed by the edge surface of annular flanges 8 and 9, said edgesurface lying in two planes converging towards the interior of the slideor the lower end thereof, as viewed in FIG. 1. The annular grooves forthe sealing rings 6 and 7 are formed with conforming convergence andtherefore the sealing rings are placed at a suitable inclination in thevalve housing for receiving the wedge-shaped disk-type slide which isoperable in conventional manner by means of a spindle 10 whose outer endportion projects outwardly through an opening at the top of the upperbody 4 of the valve housing 1 and carries a handwheel 11 at said endportion.

Provided on the part of the spindle 10 extending through the openingtherefor in the upper body 4 of the valve housing 1 are three annulargrooves two of which accommodate an O- ring-type gasket 12 and 13,respectively, while the third innermost groove accommodates a washer 14which engages the bottom surface of an annular groove on the inner sideof the valve housing around the opening for the spindle 10. The latteris axially fixed in the valve housing with the aid of the washer l4 andthe hub 15 of the handwheel 11, said hub engaging a flat surface or awasher 16 at the top of the upper body 4 of the valve housing and beingheld by means of a nut 17. By rotation of the handwheel 11 the slide 5can be moved up and down in conventional manner in the valve housingsince the axially fixed but rotatable spindle I0 is threaded and screwedinto a threaded bore in theslide 5. At the bottom the valve housing hasa threaded drain closed by means of a screw plug I8 which can be openedfrom outside, and the sockets 2, 3 are provided with bolt holes 19 forconnection with the pipes of a pipeline.

The manufacture of the valve in FIG. I is illustrated in FIGS. 2 and 3.First, the slide 5 and the sealing rings 6 and 7 are manufactured frommetal, such as brass or bronze cast in ingot molds or red brass cast insand, and the said details are worked into a condition ready for use.The slide is then mounted on a supporting rod 21 which is inserted inthe hole in the slide for the valve rod and is centered in the slidewith the aid of washers 22. The sealing rings 6 and 7 are detachablysecured to the slide in the position in which they are shown in FIG. 2,that is, the sealing rings 6 and 7 are mounted on the sealing surfacesof the annular slide flanges 8, 9 and connected to the slide in asuitable manner, for instance by adhesive or other suitable detachablebond. This being made, the unit comprising the slide 5, the sealingrings 6 and 7, and the rod 21 is enclosed in the core 23 so that theslide and the sealing rings are surrounded by that part 24 of the corewhich is to shape the hollow space in the upper body 4 of the valvehousing. This part 24 of the core is connected or formed integrally withthe remaining part of the core which is to shape the hollow space in thelower body of the valve housing 1, i.e. including the hollow spaces forthe sockets 2 and 3, projections 25 and 26 being formed on the core 23around the supporting rod 21 for shaping the spindle opening 27 at thetop of the upper body 4 of the valve housing, and the drain 28 at thebottom of the lower body of the valve housing.

The core 23 is given a suitable outer contour to facilitate forming thegrooves 30 and 31 for the sealing rings 6 and 7. These grooves aremachined after the casting of the valve housing to be smooth and to fitthe sealing rings 6 and 7. Also the core 23 is given suitable tolerancesto permit subsequent machining of the opening 27 for the spindle l0 andcutting internal threads in the drain 28 for the screw plug 18 closingsaid drain.

The core is preferably provided with a pair of parallel andsubstantially diametrical grooves extending in the longitudinaldirection of the slide to shape a pair of guide ribs 32 on the innerside of the valve housing, and the slide is formed with a pair of guidestuds 33 (see FIG. 3) for engaging said guide ribs. It may be suitableto shape said ribs in such a way that they are mutually offset toopposite sides of diametrical planes extending in the direction ofmotion of the slide in the valve housing, in which case the slide at thecasting operation must be placed in the core in an angular positiondeviating from the normal operating position so that the guide studs 33lie laterally of the grooves in the core and can be moved to positionsopposite the guide ribs 32 (see left-hand part of FIG. 3) after casting.The core must then be so dimensioned as to allow said position of theslide and moreover the core must be so dimensioned that the sealingrings 6 and 7 can be moved downwards from the position shown in FIG. 2past the inwardly directed flanges 34 and 35 at the ends of which thegrooves 30 and 31 for the sealing rings 6 and 7 are to be provided, asindicated in FIG. 2. These flanges 34 and 35 are shaped in such a waythat their end surfaces will take an inclination corresponding to thatof the end surfaces of the slide flanges 8 and 9.

The right-hand part of FIG. 3 shows a possible modification of the guidefor the slide 5. In this modification the guide ribs 32' are madeslightly shorter so as to terminate a short distance beneath the top ofthe hollow space in the valve housing, and the studs 33' of the slideare made slightly longer and are formed with grooves for accommodatingthe guide ribs, the slide being enclosed in the core in such a positionas to be located during casting a slight distance above its normal,fully open position, i.e. in such a way that the studs 33 go free fromthe upper ends of the guide ribs 32. After casting the slide is loweredsomewhat to permit insertion of the ends of the guide ribs 32 in thegrooves provided in the studs 33', whereupon the slide is fixed on thespindle so that it cannot any more be pulled up to a position in whichthe studs 33' are disengaged from the guide ribs. By this arrangementthe slide will be guided and securely retained against rotation inopposite directions, which will spare the sealing rings 6 and 7 andprevents jamming of the slide.

Having been given its final shape the core is fixed in conventionalmanner in a mold for casting the valve housing 1, for instance in castiron, which is customary. After casting, the core is removed and theannular grooves 30 and 31 are provided in the flanges 34 and 35 bymachining with the aid of tools introduced through the ports of thesockets 2 and 3. If necessary, the supporting rod 21 is first removed,but the slide 5 and the spindle 10 are retained in the upper body 4 ofthe valve housing in the positions shown in FIG. 2. Machining can beeffected with the upper body of the valve housing turned downwards.After the provision of the grooves 30 and 31 the sealing rings 6 and 7are released and moved down into the lower body of the valve housing,whereupon they are positioned in the grooves 30 and 31 in a suitablemanner, for instance by hammering.

After machining of the hole 27 at the top of the upper body 4 of thevalve housing, through which hole the spindle 10 is to extend, and aftercutting internal threads in the drain 28 which is to be closed by meansof the plug 18, the spindle 10 is mounted in the slide 5, the washer 14being first introduced through one of the sockets 2 and 3 and passedonto the spindle. For this purpose, the washer 14 is divided and theparts thereof are yieldingly kept together by a spring clip 36 of bronzeor other suitable material which permits sufficient spreading of thehalves of the washer for passing the latter onto the spindle, and whichthen compresses the washer halves in the groove provided for said washerin the spindle 10, after the washer has been moved up to said groove byrotation of the spindle in the slide. The spindle can then be raised sothat the washer is moved into the groove 37 provided for said washer inthe valve housing, whereupon the handwheel 11 is secured in position sothat the spindle is axially fixed in the valve housing.

The necessary treatment for finishing the valve housing on the outerside thereof are performed by some conventional method.

It has been assumed in the foregoing that the slide is in an integralpiece and thus consists throughout of the same material. For economicalreasons, however, it may be desirable to cast the slide from cast ironand to provide it with sealing rings of another metal secured bydovetailed grooves or in any other manner. It is also conceivable tosubstitute for the metal sealing rings 6 and 7 in the valve housing,valve seats which are machined on the valve housing flanges 34 and 35(see FIG. 2) instead of the grooves 30 and 31.

It is also conceivable to place the metal rings 6 and 7 in anotherposition in the core than that shown in FIG. 2. For instance, they can edisposed closely beneath the slide 5 or some distance beneath it, if thesludge well at the bottom of the valve housing is made sufficientlybroad and deep for the purpose. If desired, the supporting rod 21 can bemade slenderer to permit close relative location of the metal rings 6and 7 beneath the slide 5, and it is also possible to substitute themetal rings for part of the rod 21 if said rings are placed inapplication against one another beneath the slide and are enclosed insaid position in the core.

FIG. 4 shows an example of a shutoff valve having a conical valve member50 which is operable in the valve housing 1 by means of a handwheel 11'and a spindle 10'. The conical valve member 50 cannot be introduced intothe valve housing if the latter is not made divisible or the connectingsockets 2 and 3 are not made unreasonably large, but no difficulty isassociated with the incorporation of the valve member 15 in questionwith a core and the casting of the valve housing in one piece, with thevalve member positioned in the valve housing.

What I claim and desire to secure by Letters Patent is: 1. A method ofmanufacturing a valve having a unitary, integrally formed housingcomprised of first and second portions with inlet and outlet ports andvalve seats located in said second portion, and a valve member movableby an operating means extending through an opening in said housingbetween a position in said first portion of said housing in which saidvalve is opened and a position adjacent said valve seats in said secondportion of said housing in which said valve is closed, comprising thesteps of:

manufacturing and completely finishing said valve member, enclosing saidvalve member in a first portion of a unitary, integrally formed core inthe position corresponding to said open position of said valve, saidcore having a second portion which is shaped so that it includes saidinlet and outlet ports and so that it may be provided with said valveseats,

fixing said core in a mould for casting,

casting said valve housing around said core so as to form said first andsecond portions of said housing around said corresponding first andsecond portions of said core,

removing said core from said housing through either said inlet or outletport, and

attaching said operating means to said valve member.

2. A method according to claim 1 further comprising the step of mountingsaid valve member on a supporting rod before it is enclosed by saidcore, said supporting rod being replaced by said operating means aftercasting.

3. A method according to claim 1 further including the steps of;

attaching manufactured sealing rings to said valve member before saidvalve member is enclosed by said first portion of said core,

providing annular valve seats for said sealing rings in said secondportion of said housing after said core has been removed, and

releasing said sealing rings from said valve member and mounting them insaid valve seats.

4. A method according to claim 3 in which the valve housing is cast withinternal guide ribs and said valve member is formed with guide studs forengagement with said guide ribs. said valve member being positioned insaid core so that said studs lie laterally of said ribs at the time ofcasting and wherein said valve member is turned after casting so thatsaid studs are in position to engage said ribs.

5. A method according to claim 3 wherein said valve housing is cast withinternal guide ribs for the valve member and the valve member is formedwith guide studs for engagement with said guide ribs and wherein saidvalve member is enclosed in said core in a position spaced from saidopen position of said valve, said guide ribs being formed in the valvehousing so that when said valve member is moved to said open positionsaid studs engage said guide ribs.

6. A method according to claim 3 wherein said sealing rings are enclosedin said core at a point extended from the end of said valve member.

1. A method of manufacturing a valve having a unitary, integrally formedhousing comprised of first and second portions with inlet and outletports and valve seats located in said second portion, and a valve membermovable by an operating means extending through an opening in saidhousing between a position in said first portion of said housing inwhich said valve is opened and a position adjacent said valve seats insaid second portion of said housing in which said valve is closed,comprising the steps of: manufacturing and completely finishing saidvalve member, enclosing said valve member in a first portion of aunitary, integrally formed core in the position corresponding to saidopen position of said valve, said core having a second portion which isshaped so that it includes said inlet and outlet ports and so that itmay be provided with said valve seats, fixing said core in a mould forcasting, casting said valve housing around said core so as to form saidfirst and second portions of said housing around said correspondingfirst and second portions of said core, removing said core from saidhousing through either said inlet or outlet port, and attaching saidoperating means to said valve member.
 2. A method according to claim 1further comprising the step of mounting said valve member on asupporting rod before it is enclosed by said core, said supporting rodbeing replaced by said operating means after casting.
 3. A methodaccording to claim 1 further including the steps of; attachingmanufactured sealing rings to said valve member before said valve memberis enclosed by said first portion of said core, providing annular valveseats for said sealing rings in said second portion of said housingafter said core has been removed, and releasing said sealing rings fromsaid valve member and mounting them in said valve seats.
 4. A methodaccording to claim 3 in which the valve housing is cast with internalguide ribs and said valve member is formed with guide studs forengagement with said guide ribs, said valve member being positioned insaid core so that said studs lie laterally of said ribs at the time ofcasting and wherein said valve member is turned after casting so thatsaid studs are in position to engage said ribs.
 5. A method according toclaim 3 wherein said valve housing is cast with internal guide ribs forthe valve member and the valve member is formed with guide studs forengagement with said guide ribs and wherein said valve member isenclosed in said core in a position spaced from said open position ofsaid valve, said guide ribs being formed in the valve housing so thatwhen said valve member is moved to said open position said studs engagesaid guide ribs.
 6. A method according to claim 3 wherein said sealingrings are enclosed in said core at a point extended from the end of saidvalve member.